We have reported that a species of DNA is associated with the cytoplasmic membranes of a continuously growing diploid, human, lymphocyte cell line, Wil-2. Cytoplasmic membrane-associated DNA (cmDNA) has been definitely differentiated from mitochondrial DNA, viral DNA, mycoplasmal DNA and the bulk of nuclear DNA. cmDNA is synthesized in the cell nucleus and then "exits" to the cytoplasm. However, only a small, select fraction of the total nuclear genetic material ever appears in the cytoplasm as cmDNA. The proposed study is designed to determine the function of cmDNA. Attempts will be made to answer the following basic questions: (1) Is cmDNA transcribed and if so, where? (2) What is the location fo cmDNA in human chromosomes? (3) Does cytoplasmic DNA like cmDNA occur as a general characteristic of animal cells? (4) Is cmDNA related to cell malignancy, and if so, how?